Glacier Lake Outburst Floods
Cumulative frequency graph of GLOFs in Nepal,
Bhutan and Tibet. The best-ft line suggests an increase in
GLOF frequency through time, although older events may be
under-reported. GLOFs also took place in Patagonia, Chile in
2008 and 2009 (Dussaillant et al., 2010)(From Richardson
and Reynolds, 2000).
06 Dec 2010 - by Riccardo Pravettoni
Glacier volume change forecasts
Oerlemans et al. (1998) conducted modelling experiments for a sample of 12 glaciers and ice caps, to determine volume changes under a range of temperature and precipitation forcings (Fig. 3). The range of glacier response is very wide, so a key issue is fnding ways to upscale the results of modelling this tiny sample of glaciers to large regions. Figure 2 shows the results of two alternative weighting procedures. Although the
absolute values o...
06 Dec 2010 - by Riccardo Pravettoni
Glacier cumulative mass balance
Compilation of available data (Fig. 1) shows that most mountain glaciers are losing mass, and that the overall rate of mass loss has increased in the last decade. For the last decade the highest mass loss per unit area has been observed in the European Alps, Patagonia, Alaska, and north-western USA/south-western Canada (Kaser et al., 2006, Lemke et al., 2007, Arendt et al., 2009).
06 Dec 2010 - by Riccardo Pravettoni
Regional flood vulnerability
Since Asia comprises a large portion of the World’s popula-
tion, and more than 40% of all the foods in the world occur
in Asia, a large number of people are affected by disasters
(Fig. 14). More than 40% of the people killed by natural di-
sasters are killed in Asia (Fig. 15). In the ten-year period from 1999–2008, 402 foods were recorded in Africa, 342 in the Americas, 259 in Europe and 649 in Asia. In the same time period close to 1 bill...
06 Dec 2010 - by Riccardo Pravettoni
Seasonal patterns of precipitation and runoff
The infuence of glaciers on seasonal distribution of river
fow is strongly dependent on annual temperature and precipitation cycles, and the proportion of the catchment occupied by glacier ice. Figure 4 compares precipitation and river fow data for heavily and lightly glacierized catchments in the European Alps and Peru. In the European Alps, runoff is greater than precipitation in summer in both heavily and lightly glacierized catchments. This...
06 Dec 2010 - by Riccardo Pravettoni
Qanat
A qanat is a water management system used to secure reliable water supply to human settlements or irrigation in semi-arid and arid regions. Probably originating in Persia, the qanat system has been adopted and developed further in large parts of Asia and Europe. Its widespread use is refected in the many names for the system and similar systems; kariz/kahan (Persian), khettara (Morocco), galeria (Spain), falaj (United Arab Emirates and Oman), ...
06 Dec 2010 - by Riccardo Pravettoni
Glacier recession and expansion in Hindu Kush-Himalayas and Central Asia
Averaged over their entire areas, within the period 1960–
2003 glaciers in Patagonia and Alaska have thinned by ap-
proximately 35 m and 25 m, respectively, whereas high
mountain glaciers in Asia have thinned by over 10 m. Data
for Patagonia and Alaska are computed from glacier surface
elevations for dozens of glaciers. In many other high moun-
tain environments such as the Himalayas and the high Andes,
where data are limited due to bo...
06 Dec 2010 - by Riccardo Pravettoni
Victims and affected people in Pakistan flood, August 2010
Seasonal fooding can occur along all the major watersheds
in the Himalayan region (Figure 11–14). The largest problems
occur in food prone areas with high population densities.
This includes parts of northeast India, south-central Nepal,
central and southern Pakistan, large parts of Bangladesh and
lower reaches of the large rivers in China. In India around
40 million people are affected by fooding annually and the
damage has been estimated...
15 Feb 2010 - by Riccardo Pravettoni
Salzach river discharge, Austrian Alps
Simulated contributions of glacier melt (frn/ice melt) to annual total runoff were calculated between 1 and 4%. In the period 1999–2000, when the glacier mass balance of Goldbergkees and Stubacher Sonnblickkees have been observed to be zero or slightly above zero, the annual contribution of glacier melt was calculated as 1% (Fig. 7). The highest monthly contribution in 2000 was 4% for the month of August, and the highest daily glacier melt was 12...
06 Dec 2010 - by Riccardo Pravettoni
Glacier shrinkage in hypothetical river basins
Downstream variation in the impact of glacier recession is
illustrated in Figure 5, which shows modelled river fows for
idealized catchments under climates representative of the
western and eastern Himalaya and a 0.06º C per year warming scenario. In the upper parts of the river basins, where
glaciers occupy 95% of the catchment area, the impact of glacier shrinkage is large. River discharges increase until mid-century, after which they de...
06 Dec 2010 - by Riccardo Pravettoni
Recent flood events in the Hindu Kush-Himalaya region
Since Asia comprises a large portion of the World’s popula-
tion, and more than 40% of all the foods in the world occur
in Asia, a large number of people are affected by disasters
(Fig. 14). More than 40% of the people killed by natural di-
sasters are killed in Asia (Fig. 15). In the ten-year period from 1999–2008, 402 foods were recorded in Africa, 342 in the Americas, 259 in Europe and 649 in Asia. In the same time period close to 1 bill...
03 Feb 2010 - by Riccardo Pravettoni